Bug#629983: libc6 install aborts with "A non-dpkg owned copy of the C library was found in /lib."

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Package: libc6
Version: 2.13-6

My poor confused brain thinks "the C library" is libc-2.13.so which is NOT
in /lib (it's in /lib/i386-linux-gnu/ and /lib/i386-linux-gnu/i686/cmov/)
so the error message is not terribly useful.

The check can't be found in /var/lib/dpkg/info/libc6.preinst (from -5),
so that doesn't tell me what's going on.

I look around and find bug #629534 which looks like the issue is with
ld.so.  Looking at my system, I do indeed have an ancient /lib/ld.so
(6 March 2001) so I start a statically linked shell (for safety) and
move it to ld.so.old.

And retry the installation of the package.  Which still fails, with
the same error message.

Finally, after a few attempts, I manage to stop the dpkg while
/var/lib/dpkg/tmp.ci/preinst exists and read *that*.  It shows me that the
pattern searched for is /lib/ld*.so*, so my adding a .old suffix doesn't
work.

Now, I really shouldn't have to go to this much trouble to understand
a freaking error message.  The offending file name is readily available in $i.
How about printing THAT rather than referring vaguely to "the C library".

Thank you!